Clinicians and patients often seek to determine the cause of disease, particularly when they believe that knowing the cause will affect management. Both scientific and public media, with their focus on genetics and the promise of individualized medicine, have heightened expectations that greater understanding of genetic information will improve health outcome. At the same time, many bodies, including most recently the Secretary's Advisory Committee on Genetic Testing, have cautioned against the too rapid adoption of genetic testing, calling for evidence of analytic validity, clinical validity, clinical utility, and social implications prior to the inclusion of genetic tests in clinical practice. Anecdotal evidence suggests that there can be a substantial gap between what clinicians and patients desire and what is thought to be appropriate practice. We propose to explore this gap. Our initial paradigms for this exploratory grant are Long QT and Brugada syndromes, which often present as sudden death, outcomes that can sometimes be averted by medical intervention. These disorders are genetically complex and as yet incompletely understood and so do not meet general criteria for clinical use. We seek to understand why clinicians nonetheless seek genetic testing for these disorders, and why investigators sometimes provide it. The results of this inquiry will provide insight into how likely it is that clinicians and researchers will adhere to the recommendations of bodies such as the SACGT and legal requirements such as CLIA, insights that could inform the regulatory approach. We also plan to develop instruments that could then be applied to other genetic tests as well to obtain a fuller understanding of the way genetic research is actually translated into practice.